The National Football League hasn’t yet calculated how much it has lost in revenue due to the shutdown of the U.S.’s most-popular sport, according to Eric Grubman , executive vice president for business ventures.

National Football League owners have little incentive to create new revenue streams because the current labor contract gives players too much of a share before accounting for costs, said Eric Grubman , the league’s executive vice president of business operations.

The National Football League’s 32 teams expect modest revenue growth this year due to a sluggish economy and uncertainty over government tax and spending decisions, said Eric Grubman, the NFL’s executive vice president and president of NFL Business Ventures.